Tiled Lateral Thyristor

ABSTRACT

A thyristor tile includes first and second PNP tiles and first and second NPN tiles. Each PNP tile is adjacent to both NPN tiles, and each NPN tile is adjacent to both PNP tiles. A thyristor includes a plurality of PNP tiles and a plurality of NPN tiles. The PNP and NPN tiles are arranged in an alternating configuration in both rows and columns. The PNP tiles are oriented perpendicular to the NPN tiles. Interconnect layers have a geometry that enables even distribution of signals to the PNP and NPN tiles.

BACKGROUND

There is an advantage to having a general design for an electroniccomponent, such as a thyristor, or silicon-controlled rectifier (SCR),that allows for the same general design to be adapted for use in a widevariety of design applications. For example, spatial constraints withinan overall integrated circuit layout can severely restrict a designchoice for placement and layout of the thyristor device, therebypotentially adversely affecting desired performance characteristicsthereof.

Additionally, it is generally very difficult to make a thyristor, orSCR, on a semiconductor-on-insulator (SOI) substrate or platform.However, given the prevalence of SOI technologies, it would beadvantageous to be able to form a thyristor device on an SOI wafer orsubstrate.

SUMMARY

In accordance with some embodiments, a thyristor tile includes first andsecond PNP tiles and first and second NPN tiles. Each PNP tile isadjacent to both NPN tiles; and each NPN tile is adjacent to both PNPtiles.

In some embodiments, the first and second PNP tiles have a firstorientation; and the first and second NPN tiles have a secondorientation that is perpendicular to the first orientation.

In some embodiments, each of the first and second PNP tiles have anN-type base region and a P-type emitter region aligned in the firstorientation; and each of the first and second NPN tiles have a P-typebase region and an N-type emitter region aligned in the secondorientation.

In some embodiments, each N-type base region is aligned in the firstorientation with the N-type emitter region of one of the first andsecond NPN tiles and is an N-type collector region of that NPN tile; andeach P-type base region is aligned in the second orientation with theP-type emitter region of one of the first and second PNP tiles and is aP-type collector region of that PNP tile.

In some embodiments, the first and second PNP tiles each have a secondN-type base region aligned in the first orientation with the firstN-type base region and the P-type emitter region; and the first andsecond NPN tiles each have a second P-type base region aligned in thesecond orientation with the first P-type base region and the N-typeemitter region.

In some embodiments, the thyristor tile further includes a firstinterconnect layer that electrically connects the N-type base regions ofthe first and second PNP tiles; a second interconnect layer thatelectrically connects the P-type base regions of the first and secondNPN tiles; a third interconnect layer that electrically connects theN-type emitter regions of the first and second NPN tiles; and a fourthinterconnect layer that electrically connects the P-type emitter regionsof the first and second PNP tiles.

In some embodiments, the thyristor tile is formed with a horizontallongitudinal dimension and a horizontal lateral dimension; the firstinterconnect layer includes 1) first island traces that electricallyconnect to the P-type emitter regions, 2) second island traces thatelectrically connect to the N-type emitter regions, 3) third islandtraces that electrically connect to the P-type base regions, and 4)first lateral, longitudinal and diagonal traces that electricallyconnect to the N-type base regions and that surround the first, secondand third island traces; the second interconnect layer includes 1)fourth island traces that electrically connect to the P-type emitterregions, 2) fifth island traces that electrically connect to the N-typeemitter regions, and 3) second lateral, longitudinal and diagonal tracesthat electrically connect to the P-type base regions and that surroundthe fourth and fifth island traces; and the third interconnect layerincludes 1) sixth island traces that electrically connect to the P-typeemitter regions, and 2) first and second sets of diagonal traces thatelectrically connect to the N-type emitter regions that are alignedalong the same diagonals and that surround the sixth island traces.

In some embodiments, the first lateral, longitudinal and diagonal tracesform first rectangular structures that surround the first island tracesand form first octagonal structures that surround the second and thirdisland traces; the second lateral, longitudinal and diagonal traces formsecond rectangular structures that surround the fifth island traces andform second octagonal structures that surround the fourth island traces;and the first and second sets of diagonal traces form rhombus structuresthat surround the sixth island traces.

In some embodiments, each NPN tile is formed within a P-well base; eachPNP tile is formed within an N-well base; and the P-well bases areadjacent to the N-well bases, except at a corner between all fourN-wells and P-wells.

In some embodiments, the first PNP tile is in a first quadrant of thethyristor tile; the first NPN tile is in a second quadrant of thethyristor tile, the second quadrant being located adjacent to the firstquadrant; the second PNP tile is in a third quadrant of the thyristortile, the third quadrant being located adjacent to the second quadrant,and the third quadrant being diagonally located from the first quadrant;and the second NPN tile is in a fourth quadrant of the thyristor tile,the fourth quadrant being located adjacent to the first and thirdquadrants, and the fourth quadrant being diagonally located from thesecond quadrant.

In some embodiments, an improved thyristor includes a plurality of thethyristor tile of claim 10. The first NPN tile in the second quadrant ofa first one of the plurality of the thyristor tile is located adjacentto the first PNP tile in the first quadrant of a second one of theplurality of the thyristor tile. A first N-type base region of the firstPNP tile in the first quadrant of the second one of the plurality of thethyristor tile is a first N-type collector region of the first NPN tilein the second quadrant of the first one of the plurality of thethyristor tile. In some embodiments, the first NPN tile in the secondquadrant of the first one of the plurality of the thyristor tile islocated adjacent to the second PNP tile in the third quadrant of a thirdone of the plurality of the thyristor tile; and a first P-type baseregion of the first NPN tile in the second quadrant of the first one ofthe plurality of the thyristor tile is a first P-type collector regionof the second PNP tile in the third quadrant of the third one of theplurality of the thyristor tile.

In accordance with some embodiments, an improved thyristor includes aplurality of PNP tiles and a plurality of NPN tiles. The PNP tiles andthe NPN tiles are arranged in an alternating configuration in both rowsand columns.

In some embodiments, each PNP tile is adjacent to at least two of theNPN tiles; and each NPN tile is adjacent to at least two of the PNPtiles.

In some embodiments, each PNP tile has at least one base region that isalso a collector region of an adjacent NPN tile; and each NPN tile hasat least one base region that is also a collector region of an adjacentPNP tile.

In some embodiments, the PNP tiles have a first orientation; and the NPNtiles have a second orientation that is perpendicular to the firstorientation.

In some embodiments, each PNP tile has first and second N-type baseregions and a P-type emitter region, the P-type emitter region beinglocated between the first and second N-type base regions, and the firstand second N-type base regions and the P-type emitter region beingaligned in the first orientation; and each NPN tile has first and secondP-type base regions and an N-type emitter region, the N-type emitterregion being located between the first and second P-type base regions,and the first and second P-type base regions and the N-type emitterregion being aligned in the second orientation.

In some embodiments, at least one of the first and second N-type baseregions of each PNP tile is aligned in the first orientation with theN-type emitter region of an adjacent one of the NPN tiles; the at leastone of the first and second N-type base regions of each PNP tile is alsoan N-type collector region of the adjacent one of the NPN tiles; atleast one of the first and second P-type base regions of each NPN tileis aligned in the second orientation with the P-type emitter region ofan adjacent one of the PNP tiles; and the at least one of the first andsecond P-type base regions of each NPN tile is also a P-type collectorregion of the adjacent one of the PNP tiles.

In some embodiments, the thyristor further includes a first interconnectlayer that electrically connects the N-type base regions of the PNPtiles and the N-type collector regions of the NPN tiles, the firstinterconnect layer including first traces that surround the P-typeemitter regions, the N-type emitter regions, and the P-type base regionsin a first plane vertically offset therefrom; a second interconnectlayer that electrically connects the P-type base regions of the NPNtiles and the P-type collector regions of the PNP tiles, the secondinterconnect layer including second traces that surround the P-typeemitter regions and the N-type emitter regions in a second planevertically offset therefrom; a third interconnect layer thatelectrically connects the N-type emitter regions of the NPN tiles, thethird interconnect layer including third traces that surround the P-typeemitter regions in a third plane vertically offset therefrom; and afourth interconnect layer that electrically connects the P-type emitterregions of the PNP tiles.

In some embodiments, the first traces form first rectangular structuresthat surround the P-type emitter regions and form first octagonalstructures that surround the N-type emitter regions and the P-type baseregions; the second traces form second rectangular structures thatsurround the N-type emitter regions and form second octagonal structuresthat surround the P-type emitter regions; and the third traces includediagonal traces that form rhombus structures that surround the P-typeemitter regions.

In some embodiments, the first, second, third and fourth interconnectlayers are configured to receive an electrical connection thereto at anypoint along any peripheral side thereof for electrical interconnectionsto other electronic components of an overall electronic circuit of whichthe thyristor is a part.

In some embodiments, the PNP tiles and the NPN tiles are formed within aCMOS process flow simultaneously with portions of MOSFET devices of anoverall electronic circuit of which the thyristor is a part.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified schematic diagram of a thyristor orsemiconductor-controlled rectifier (SCR).

FIG. 2 is a simplified top view layout of an example horizontal orlateral thyristor tile, in accordance with some embodiments.

FIGS. 3 and 4 are simplified cross section diagrams of the horizontal orlateral thyristor tile shown in FIG. 2, in accordance with someembodiments.

FIGS. 5-7 are simplified diagrams of example horizontal or lateralthyristor devices formed with a plurality of the horizontal or lateralthyristor tile shown in FIGS. 2-4, in accordance with some embodiments.

FIGS. 8-11 are simplified diagrams of example interconnect layers andvias for electrically connecting components of an example horizontal orlateral thyristor device formed with a plurality of the horizontal orlateral thyristor tile shown in FIGS. 2-4, in accordance with someembodiments.

FIGS. 12-15 are simplified current-voltage graphs showing theperformance of an example horizontal or lateral thyristor device formedwith a plurality of the horizontal or lateral thyristor tile shown inFIGS. 2-4, in accordance with some embodiments.

FIGS. 16-18 are simplified current-voltage graphs showing the results oftransmission line pulse (TLP) tests, for example, horizontal or lateralthyristor devices formed with a plurality of the horizontal or lateralthyristor tile shown in FIGS. 2-4, in accordance with some embodiments.

FIG. 19 is a simplified schematic diagram of a thyristor with optionaltriggers.

FIGS. 20-26 are simplified current-voltage graphs showing theperformance of an example horizontal or lateral thyristor device formedwith a plurality of the horizontal or lateral thyristor tile shown inFIGS. 2-4, in accordance with some embodiments.

FIG. 27 is a simplified flowchart for an example method of fabricatingthe thyristor tile shown in FIGS. 1-4.

DETAILED DESCRIPTION

A simplified schematic diagram of a thyristor 100 is shown in FIG. 1;and a simplified top view layout of an example horizontal or lateralthyristor tile 200 is shown in FIG. 2, in accordance with someembodiments. Disclosed herein is an improved design, geometry,structure, placement or layout for the thyristor 100 incorporatingmultiple instances of the horizontal or lateral thyristor tiles 200formed from individual PNP tiles (or “PNP BJT sub-tiles”) and NPN tiles(or “NPN BJT sub-tiles”), as described below. The design of thethyristor tiles 200 allows for a high level of flexibility indesign-stage control over device placement and layout, structuralfeature geometry, and operating parameters of the resulting horizontalor lateral thyristor 100 that can be easily incorporated within thespatial constraints of an overall integrated circuit layout with littleor no adverse effects on the available circuit area, includingembodiments advantageously formed on a semiconductor-on-insulator (SOI)wafer. Additionally, at least some portions of the thyristor 100 may beformed simultaneously with, i.e., during an overall complementarymetal-oxide-semiconductor (CMOS) process flow, some regions ofmetal-oxide-semiconductor field-effect transistors (MOSFETs)incorporated in the overall electronic circuit within an integratedcircuit of which the thyristor 100 is a part, thereby enhancing ease ofincorporation of the thyristor 100 into the overall electronic circuit,particularly for integrated circuits formed in and on an SOI wafer.Furthermore, electrical interconnect (or metal) layers of the thyristor100 allow for electrical connections to the thyristor at any or allsides thereof; thereby further enhancing the ease with which thethyristor 100 can be incorporated in the overall electronic circuit. Inaddition, the design or configuration of the thyristor 100 (includingthe thyristor tiles 200 and the electrical interconnect layers) allowsfor flexible triggering thereof. Additional advantages or improvementswill be described below or will be apparent from the followingdescription.

As shown in FIG. 1, the thyristor 100 generally includes a PNP BJT(bipolar junction transistor) device 101 and an NPN BJT device 102. ThePNP BJT device 101 includes a PNP P-type emitter 103, and the NPN BJTdevice 101 includes an NPN N-type emitter 104. Additionally, the PNP BJTdevice 101 includes a PNP N-type base 105 and the NPN BJT device 102includes an NPN N-type collector 106 that are formed or connectedtogether as an N-type base/collector (or a PNP-base/NPN-collector)105/106. Also, the NPN BJT device 102 includes an NPN P-type base 107and the PNP BJT device 101 includes a PNP P-type collector 108 that areformed or connected together as a P-type base/collector (or anNPN-base/PNP-collector) 107/108.

As shown in FIG. 2, the thyristor tile 200 generally includes first andsecond PNP tiles 201 and 202 and first and second NPN tiles 203 and 204,which are not necessarily drawn to scale. Each PNP tile 201 and 202 isadjacent to both NPN tiles 203 and 204, and each NPN tile 203 and 204 isadjacent to both PNP tiles 201 and 202. However, the PNP tiles 201 and202 are not adjacent to each other, and the NPN tiles 203 and 204 arenot adjacent to each other. Instead, the PNP tiles 201 and 202 areoffset diagonally from each other (e.g., top left to bottom right), andthe NPN tiles 203 and 204 are offset diagonally from each other (e.g.,top right to bottom left). It is understood, however, that the specifictop/bottom and left/right locations for the tiles 201-204 are providedfor illustrative and explanatory purposes only since the relativelocations for the PNP tiles 201 and 202 can be switched with that of theNPN tiles 203 and 204.

Additionally, the thyristor tile 200 may be part of an overallhorizontal or lateral thyristor device, which further includes aplurality of thyristor tiles (not shown, but each similar to 200), suchthat PNP tiles (each similar to 201 or 202) and NPN tiles (each similarto 203 or 204) are arranged in an alternating configuration in both rowsand columns, as described below with respect to FIGS. 5-7. Thus, eachPNP or NPN type of tile is adjacent to at least two tiles of theopposite type (e.g., two tiles at a row/column corner, three tiles at arow or column edge, or four tiles within an interior of the rows andcolumns).

Each PNP tile 201 and 202 generally includes a P-type emitter region 201a and 202 a, a first N-type base region 201 b and 202 b, a second N-typebase region 201 c and 202 c, an N-well base region 201 d and 202 d,emitter contacts 201 e and 202 e, first base contacts 201 f and 202 f,and second base contacts 201 g and 202 g. Similarly, each NPN tile 203and 204 generally includes an N-type emitter region 203 a and 204 a, afirst P-type base region 203 b and 204 b, a second P-type base region203 c and 204 c, a P-well base region 203 d and 204 d, emitter contacts203 e and 204 e, first base contacts 203 f and 204 f, and second basecontacts 203 g and 204 g. The emitter regions 201 a, 202 a, 203 a and204 a are square shaped structures in the center of the N-well andP-well base regions 201 d, 202 d, 203 d and 204 d, respectively. Thebase regions 201 b/c, 202 b/c, 203 b/c and 204 b/c are rectanglesadjacent to either the longitudinal or the lateral edges of the N-welland P-well base regions 201 d, 202 d, 203 d and 204 d, respectively. Theemitter and base regions are, thus, symmetrical with respect to thecenter of the tiles 201-204. The resulting structures are, thus, nearlyidentical, but rotated 90 degrees or oriented perpendicular to eachother. Additional elements or details may not be shown for simplicity;whereas other elements may be shown, but not labeled to preventovercrowding of the drawing.

For each PNP or NPN tile 201-204, the corresponding collector region isprovided by an adjacent P-type or N-type base region of an adjacent PNPor NPN tile 201-204. For example, the first N-type base region 201 b and202 b of each PNP tile 201 and 202 is also an N-type collector regionfor the adjacent NPN tile 203 and 204, respectively. Similarly, thefirst P-type base region 203 b and 204 b of each NPN tile 203 and 204 isalso a P-type collector region for the adjacent PNP tile 202 and 201,respectively. Additionally, since the thyristor tile 200 may be part ofan overall horizontal or lateral thyristor device, which furtherincludes a plurality of thyristor tiles (not shown, but each similar to200), the second N-type base region 201 c and 202 c of each PNP tile 201and 202 may also be an N-type collector region for another adjacent NPNtile (similar to 203 and 204), unless the PNP tile 201 or 202 is at anedge or corner of the overall thyristor device, such that there is noadditional NPN tile adjacent to the second N-type base region 201 c or202 c. Similarly, the second P-type base region 203 c and 204 c of eachNPN tile 203 and 204 may also be a P-type collector region for anotheradjacent PNP tile (similar to 201 and 202), unless the NPN tile 203 or204 is at an edge or corner of the overall thyristor device, such thatthere is no additional PNP tile adjacent to the second P-type baseregion 203 c or 204 c. Therefore, the base regions 201 b/c, 202 b/c, 203b/c and 204 b/c may also be referred to herein as collector regions 201b/c, 202 b/c, 203 b/c and 204 b/c or base/collector regions 201 b/c, 202b/c, 203 b/c and 204 b/c (for each base region 201 b/c, 202 b/c, 203 b/cor 204 b/c that is also a collector region). In a similar vein, the basecontacts 201 f/g, 202 f/g, 203 f/g and 204 f/g (corresponding to thebase regions 201 b/c, 202 b/c, 203 b/c and 204 b/c, respectively) mayalso be referred to herein as collector contacts 201 f/g, 202 f/g, 203f/g and 204 f/g or base/collector contacts 201 f/g, 202 f/g, 203 f/g and204 f/g (for each corresponding base region that is also a collectorregion) Additionally, although the tiles 201-204 are described as PNPand NPN BJT tiles, it is understood that the collector region for eachtype of BJT tile lies outside the BJT tile in an adjacent BJT tile ofthe opposite type.

The emitter regions 201 a, 202 a, 203 a and 204 a and the base/collectorregions 201 b/c, 202 b/c, 203 b/c and 204 b/c are generally formed asstructural islands in the corresponding N-well and P-well base regions201 d, 202 d, 203 d and 204 d. The N-well and P-well base regions 201 d,202 d, 203 d and 204 d, thus, serve as the base for a BJT formed by eachemitter region 201 a, 202 a, 203 a and 204 a and corresponding collectorregion 204 b, 203 b, 201 b and 202 b, respectively, as indicated by PNPand NPN BJT schematics 201 h, 202 h, 203 h and 204 h overlaying thetiles 201-204. Additionally, since the thyristor tile 200 may be part ofan overall thyristor device, which further includes a plurality ofthyristor tiles (not shown, but each similar to 200), the N-well andP-well base regions 201 d, 202 d, 203 d and 204 d may also serve as thebase for a BJT formed by each emitter region 201 a, 202 a, 203 a and 204a and another corresponding collector region of another adjacent NPN orPNP tile (similar to 201-204), except for the tiles 201-204 that are atan edge or corner of the overall thyristor device. Therefore, incomparison with the schematic diagram of the thyristor 100 (FIG. 1), theP-type emitter regions 201 a and 202 a generally correspond to the PNPP-type emitter 103, the N-type base/collector regions 201 b/c and 202b/c generally correspond to the N-type base/collector 105/106, theP-type base/collector regions 203 b/c and 204 b/c generally correspondto the P-type base/collector 107/108, and the N-type emitter regions 203a and 204 a generally correspond to the NPN N-type emitter 104.

An optional opening or hole 205 is shown at the corners of all fourtiles 201-204, where all four tiles 201-204 would otherwise cometogether at a shared corner point, so that each tile 201-204 (or theN-well and P-well base regions 201 d, 202 d, 203 d and 204 d) has agenerally octagonal shape. The hole 205 may be filled with intrinsicsilicon, an N-type low doped silicon, or an insulating material. Thehole 205, thus, prevents the PNP tiles 201 and 202 from contacting eachother, and prevents the NPN tiles 203 and 204 from contacting eachother, so that these components are not shorted out, but areelectrically isolated from each other. Additionally, since the thyristortile 200 may be part of an overall horizontal or lateral thyristordevice, which further includes a plurality of thyristor tiles (notshown, but each similar to 200), there is a similar hole at the sharedcorner point of every possible group of four tiles 201-204, except forthe tiles 201-204 that are at an edge or corner of the overall thyristordevice, such that there is no additional NPN or PNP tile adjacentthereto.

In some embodiments, the thyristor tile 200 is characterized as havingfour quadrants, the top left being a first quadrant (having the firstPNP tile 201), the top right being a second quadrant (having the firstNPN tile 203, and being adjacent to the first quadrant), the bottomright being a third quadrant (having the second PNP tile 202, and beingadjacent to the second quadrant and diagonally located from the firstquadrant), and the bottom left being a fourth quadrant (having thesecond NPN tile 204, and being adjacent to the first and third quadrantsand diagonally located from the second quadrant). Consequently, sincethe thyristor tile 200 may be part of an overall horizontal or lateralthyristor device, which further includes a plurality of thyristor tiles(not shown, but each similar to 200), the first PNP tile 201 in thefirst quadrant of the thyristor tile 200 is located laterally adjacentto the first NPN tile in the second quadrant (or longitudinally adjacentto the second NPN tile in the fourth quadrant) of another thyristortile, unless the first PNP tile 201 is at an edge or corner of theoverall thyristor device. Additionally, the first NPN tile 203 in thesecond quadrant of the thyristor tile 200 is located laterally adjacentto the first PNP tile in the first quadrant (or longitudinally adjacentto the second PNP tile in the third quadrant) of another thyristor tile,unless the first NPN tile 203 is at an edge or corner of the overallthyristor device. Additionally, the second PNP tile 202 in the thirdquadrant of the thyristor tile 200 is located laterally adjacent to thesecond NPN tile in the fourth quadrant (or longitudinally adjacent tothe first NPN tile in the second quadrant) of another thyristor tile,unless the second PNP tile 202 is at an edge or corner of the overallthyristor device. Additionally, the second NPN tile 204 in the fourthquadrant of the thyristor tile 200 is located laterally adjacent to thesecond PNP tile in the third quadrant (or longitudinally adjacent to thefirst PNP tile in the first quadrant) of another thyristor tile, unlessthe second NPN tile 204 is at an edge or corner of the overall thyristordevice. It is understood, however, that the specific top/bottom andleft/right locations for the quadrants and/or the specific relationshipsbetween the quadrants are provided for illustrative and explanatorypurposes only, since the relative locations for the PNP tiles 201 and202 can be switched with that of the NPN tiles 203 and 204, and thequadrants can be rotated left or right and/or flipped longitudinally orlaterally.

As mentioned above, the example horizontal or lateral thyristor tile 200may be part of an overall horizontal or lateral thyristor device. Inthis sense, the terms “horizontal” and “lateral” refer to the plane ofthe thyristor tile 200 shown in FIG. 2. Therefore, in some embodiments,the thyristor tile 200 is generally characterized as being formed withina horizontal or lateral length or longitudinal dimension (in directionY) and within a horizontal or lateral width or lateral dimension (indirection X) in the horizontal plane. Additionally, the emitter region201 a and the base regions 201 b/c of the first PNP tile 201 aregenerally characterized as having (or being aligned in) a firstorientation (e.g., in the lateral dimension, direction X); and theemitter region 202 a and the base regions 202 b/c of the second PNP tile202 are also generally characterized as having (or being aligned in) thefirst orientation. Similarly, the emitter region 203 a and the baseregions 203 b/c of the first NPN tile 203 are generally characterized ashaving (or being aligned in) a second orientation (e.g., in thelongitudinal dimension, direction Y) that is perpendicular to the firstorientation; and the emitter region 204 a and the base regions 204 b/cof the second NPN tile 204 are also generally characterized as having(or being aligned in) the second orientation. Furthermore, each N-typebase region 201 b or 202 b of the PNP tile 201 or 202 is aligned in thefirst orientation with the N-type emitter region 203 a or 204 a,respectively, of the adjacent NPN tile 203 or 204 for which the N-typebase region 201 b or 202 b is also the N-type collector region; andunless the PNP tile 201 or 202 is at an edge or corner of the overallthyristor device, each N-type base region 201 c or 202 c of the PNP tile201 or 202 is aligned in the first orientation with the N-type emitterregion (similar to 203 a or 204 a) of an adjacent NPN tile (similar to203 or 204) for which the N-type base region 201 c or 202 c is also theN-type collector region. Similarly, each P-type base region 203 b or 204b of the NPN tile 203 or 204 is aligned in the second orientation withthe P-type emitter region 202 a or 201 a, respectively, of the adjacentPNP tile 202 or 201 for which the P-type base region 203 b or 204 b isalso the P-type collector region; and unless the NPN tile 203 or 204 isat an edge or corner of the overall thyristor device, each P-type baseregion 203 c or 204 c of the NPN tile 203 or 204 is aligned in thesecond orientation with the P-type emitter region (similar to 202 a or201 a) of an adjacent PNP tile (similar to 202 or 201) for which theP-type base region 203 c or 204 c is also the P-type collector region.

If a PNP or NPN tile (e.g., 201-204) is at a row/column corner of theoverall thyristor device, then that tile has only one collector regionand only one of its base regions is used as a collector region foranother tile. If a PNP or NPN tile (e.g., 201-204) is at a row or columnedge of the overall thyristor device, and if the alignment of theemitter and base regions of the PNP or NPN tile is oriented or alignedparallel with the edge, then that tile has only one collector region,but both of its base regions are used as collector regions for anothertile. If a PNP or NPN tile (e.g., 201-204) is at a row or column edge ofthe overall thyristor device, and if the alignment of the emitter andbase regions of the PNP or NPN tile is oriented or aligned perpendicularto the edge, then that tile has two collector regions, but only one ofits base regions is used as a collector region for another tile.

FIGS. 3 and 4 show simplified example cross sections of the thyristortile 200 taken along section, or cut, lines 206 and 207, respectively,in accordance with some embodiments. FIGS. 3 and 4 further illustrate anexample of the layout and structural feature geometry of the thyristortile 200, and are not necessarily drawn to scale. FIGS. 3 and 4illustrate that the thyristor tile 200 is generally formed within avertical thickness (in direction Z), as well as within theaforementioned horizontal or lateral length or longitudinal dimension(in direction Y) and the horizontal or lateral width or lateraldimension (in direction X) in the horizontal plane.

FIG. 3 (cross section through cut line 206) shows an example crosssection with the second PNP tile 202 on the right and the second NPNtile 204 on the left. (A similar cross section, not shown, wouldillustrate the first PNP tile 201 and the first NPN tile 203 in asimilar manner using reference numbers with appropriate designations forthe tiles 201 and 203.) FIG. 3 shows an active region containing theP-type emitter region 202 a, the first and second N-type base/collectorregions 202 b/c, the N-well base region 202 d, the emitter contacts 202e, and the first and second base/collector contacts 202 f/g of thesecond PNP tile 202, and the N-type emitter region 204 a, the P-wellbase region 204 d, and the emitter contacts 204 e of the second NPN tile204. The active region also contains a P+ emitter connector region 202 iand N+ base/collector (or “base” or “collector”) connector regions 202j/k of the second PNP tile 202, and an N+ emitter connector region 204 iof the second NPN tile 204. Additionally, a buried oxide (BOX) layer 301and an underlying substrate 302 are shown for embodiments formed in andon an SOI wafer. The BOX layer 301 is optional, since other embodimentsmay be formed in and on a bulk semiconductor wafer, i.e., without aburied oxide. Furthermore, a field oxide layer 303 is shown overlyingthe active region. The first N-type base/collector region 202 b, theP-well base region 204 d, and the N-type emitter region 204 a form acollector, base and emitter, respectively, of an NPN BJT device, asindicated by an NPN BJT schematic 304 overlaying the cross section, butwith the base connector outside the plane of this cross section.

FIG. 4 (cross section through cut line 207) shows an example crosssection with the first PNP tile 201 on the right and the second NPN tile204 on the left. (A similar cross section, not shown, would illustratethe second PNP tile 202 and the first NPN tile 203 in a similar mannerusing reference numbers with appropriate designations for the tiles 202and 203.) FIG. 4 shows the active region containing the P-type emitterregion 201 a, the N-well base region 201 d, and the emitter contacts 201e of the first PNP tile 201, and the N-type emitter region 204 a, thefirst and second P-type base/collector regions 204 b/c, the P-well baseregion 204 d, the emitter contacts 204 e, the first and secondbase/collector contacts 204 f/g, and the N+ emitter connector region 204i of the second NPN tile 204. The active region also contains a P+emitter connector region 201 i of the first PNP tile 201, and a P+base/collector (or “base” or “collector”) connector regions 204 j/k ofthe second NPN tile 204. Additionally, the buried oxide (BOX) layer 301and the underlying substrate 302 are shown for embodiments formed in andon an SOI wafer. Furthermore, the field oxide layer 303 is shownoverlying the active region. The first P-type base/collector region 204b, the N-well base region 201 d, and the P-type emitter region 201 aform a collector, base and emitter, respectively, of a PNP BJT device,as indicated by a PNP BJT schematic 401 overlaying the cross section,but with the base connector outside the plane of this cross section.

To form the structures shown in FIGS. 3 and 4, the N-well base regions201 d and 202 d and the P-well base region 204 d are epitaxially grownon the buried oxide layer 301 or implanted (e.g., with appropriate N orP type dopants, respectively) into an appropriate semiconductor layer(e.g., an intrinsic silicon layer, an N-minus layer, or a P-minus layer)overlying the buried oxide layer 301. The first and second N-typebase/collector regions 202 b/c and the N-type emitter region 204 a areimplanted (e.g., with an appropriate N type dopant) into the N-well baseregion 202 d and the P-well base region 204 d, respectively. The firstand second N-type base/collector regions 202 b/c and the N-type emitterregion 204 a may generally have a higher net active implantconcentration than that of the N-well base regions 201 d and 202 d. TheP-type emitter regions 201 a and 202 a and the P-type base/collectorregions 204 b/c are implanted (e.g., with an appropriate P type dopant)into the N-well base regions 201 d and 202 d and the P-well base region204 d, respectively. The P-type emitter regions 201 a and 202 a and theP-type base/collector regions 204 b/c may generally have a higher netactive implant concentration than that of the P-well base region 204 d.The N+ base/collector connector regions 202 j/k and the N+ emitterconnector region 204 i (along with other N+ connector regions not shownor labeled in the drawings) are implanted (e.g., with an appropriate Ntype dopant) into the first and second N-type base/collector regions 202b/c and the N-type emitter region 204 a, respectively. The N+base/collector connector regions 202 j/k and the N+ emitter connectorregion 204 i may generally have a higher net active implantconcentration than that of the first and second N-type base/collectorregions 202 b/c and the N-type emitter region 204 a. This higher netactive implant concentration provides a highly doped ohmic contactbetween the first and second N-type base/collector regions 202 b/c andthe first and second base/collector contacts 202 f/g, respectively, andbetween the N-type emitter region 204 a and the emitter contacts 204 e.The P+ emitter connector regions 201 i and 202 i and the P+base/collector connector regions 204 j/k (along with other P+ connectorregions not shown or labeled in the drawings) are implanted (e.g., withan appropriate P type dopant) into the P-type emitter regions 201 a and202 a and the P-type base/collector regions 204 b/c, respectively. TheP+ emitter connector regions 201 i and 202 i and the P+ base/collectorconnector regions 204 j/k may generally have a higher net active implantconcentration than that of the P-type emitter regions 201 a and 202 aand the P-type base/collector regions 204 b/c. This higher net activeimplant concentration provides a highly doped ohmic contact between theP-type emitter regions 201 a and 202 a and the emitter contacts 201 eand 202 e, respectively, and between the first and second P-typebase/collector regions 204 b/c and the first and second base/collectorcontacts 204 f/g, respectively. The field oxide layer 303 is depositedover a top surface of the active region. The emitter contacts 201 e, 202e and 204 e and the base/collector contacts 202 f/g and 204 f/g areformed through the field oxide layer 303 to electrically contact the P+emitter connector region 201 i, 202 i, the N+ emitter connector region204 i, the N+ base/collector connector regions 202 j/k, and the P+base/collector connector regions 204 j/k, respectively. Additionalelectrical interconnect (e.g., metal) layers alternating with insulatorlayers (e.g., with electrical vias therethrough) are deposited over thecontacts 201 e, 202 e/f/g and 204 e/f/g and the field oxide layer 303,as described below with respect to FIGS. 8-11.

FIGS. 2-4 illustrate how the PNP and NPN tiles (or subtiles) 201-204form the thyristor tile 200 of an overall thyristor device, or a portionthereof. The placement of the emitter regions, base regions andcollector regions show how the thyristor device is a horizontal orlateral current flow device. FIGS. 5-7, on the other hand, illustratehow a plurality of the thyristor tile 200 (i.e., a plurality of the PNPtiles 201 and 202 and a plurality of the NPN tiles 203 and 204) can beused to form overall horizontal or lateral thyristor devices, e.g., thethyristor 100 (FIG. 1), in a manner that allows the structure of thethyristor to be scaled in accordance with the available area within theintegrated circuit and to provide ESD (electrostatic discharge)protection for the integrated circuit. The high level of flexibility inthe design-stage control of device placement, layout, and structuralfeature geometry allows for little or no need to change the integratedcircuit layout to accommodate the resulting thyristor device.

The above-described structural feature geometry of the thyristor tile200 enables a high level of flexibility in design-stage control overdevice layout for the resulting thyristor device, as illustrated bylateral thyristor devices 500, 600 and 700 in FIGS. 5, 6 and 7,respectively. The lateral thyristor devices 500, 600 and 700 are formedwith a plurality of the lateral thyristor tile 200 arranged in a varietyof overlapping configurations. The example configurations for thethyristor devices 500, 600 and 700 are shown for illustrative andexplanatory purposes only. Other examples may have a variety of otherappropriate configurations with other numbers of thyristor tiles thatconnect or overlap in the manner described herein.

The thyristor device 500 (FIG. 5) includes four thyristor tiles 501-504.Each thyristor tile 501-504 is similar to the thyristor tile 200, soeach thyristor tile 501-504 includes two PNP tiles (501 a/b, 502 a/b,503 a/b and 504 a/b) and two NPN tiles (501 c/d, 502 c/d, 503 c/d and504 c/d). Therefore, the thyristor tiles 501-504 are arranged in a 2×2array or grid of rows and columns, and the PNP and NPN tiles (501 a-d,502 a-d, 503 a-d and 504 a-d) are arranged in an alternatingconfiguration in a 4×4 array or grid of both rows and columns. In otherembodiments, additional thyristor tiles 200 could be added to thisconfiguration to make a larger, wider or longer overall thyristordevice. Adjacent PNP and NPN tiles (501 a-d, 502 a-d, 503 a-d and 504a-d) share base/collector regions, base/collector connector regions, andbase/collector contacts as described above.

The thyristor device 600 (FIG. 6) includes four thyristor tiles 601-604.Each thyristor tile 601-604 is similar to the thyristor tile 200, soeach thyristor tile 601-604 includes two PNP tiles (601 a/b, 602 a/b,603 a/b and 604 a/b) and two NPN tiles (601 c/d, 602 c/d, 603 c/d and604 c/d). Therefore, the thyristor tiles 601-604 are arranged in a 1×4array or grid of rows and columns, and the PNP and NPN tiles (601 a-d,602 a-d, 603 a-d and 604 a-d) are arranged in an alternatingconfiguration in a 2×8 array or grid of both rows and columns. In otherembodiments, additional thyristor tiles 200 could be added to thisconfiguration to make a larger, wider or longer overall thyristordevice. Adjacent PNP and NPN tiles (601 a-d, 602 a-d, 603 a-d and 604a-d) share base/collector regions, base/collector connector regions, andbase/collector contacts as described above.

The thyristor device 700 (FIG. 7) includes four thyristor tiles 701-704.Each thyristor tile 701-704 is similar to the thyristor tile 200, soeach thyristor tile 701-704 includes two PNP tiles (701 a/b, 702 a/b,703 a/b and 704 a/b) and two NPN tiles (701 c/d, 702 c/d, 703 c/d and704 c/d). Therefore, the thyristor tiles 701-704 are arranged in a 2×3array or grid of rows and columns, and the PNP and NPN tiles (701 a-d,702 a-d, 703 a-d and 704 a-d) are arranged in an alternatingconfiguration in a 4×6 array or grid of both rows and columns; however,some of the row/column locations are empty, whereas other row/columnlocations are occupied. In other embodiments, additional thyristor tiles200 could be added to this configuration to make a larger, wider orlonger overall thyristor device. Adjacent PNP and NPN tiles (701 a-d,702 a-d, 703 a-d and 704 a-d) share base/collector regions,base/collector connector regions, and base/collector contacts asdescribed above.

Variations on the configurations shown in FIGS. 5-7 can be implementedto form the thyristor 100 (FIG. 1) by using almost any available spacebetween other electronic components of an overall electronic circuit ofwhich the thyristor 100 is a part. The use of a plurality of thethyristor tiles 200 thereby enhances the ease of incorporation of thethyristor 100 into the overall electronic circuit. On the other hand,conventional circuit layout techniques for thyristor devices generallyrequire that thyristor tiles or cells be arranged in a rectangularstructure to form the thyristor device. In order to fit the rectangularstructure into an overall circuit layout, therefore, the footprint ofthe overall circuit layout might have to be increased to providesufficient space for the rectangular structure, thereby potentiallyresulting in having to make revisions to the overall circuit layout.Thus, the ability of the thyristor tiles 200 to be arranged in a varietyof multiple complex shapes, as illustrated by the examples in FIGS. 5-7,allows for optimum usage of available space within an existing overallcircuit layout, thereby minimizing any potential need to revise theoverall circuit layout to fit the resulting thyristor device into theoverall circuit layout. The time for and cost of designing the thyristordevice and the overall circuit are thus reduced.

FIGS. 8-11 show simplified diagrams of novel example interconnect layers(e.g., electrical interconnect or metal layers 800, 900, 1000 and 1100)and the underlying contacts or vias for electrically connectingcomponents of an example horizontal or lateral thyristor device formedwith a plurality of the thyristor tile 200 shown in FIGS. 2-4, inaccordance with some embodiments. Each interconnect layer 800, 900, 1000and 1100 corresponds to and forms a terminal of the thyristor device,e.g., the interconnect layer 800 corresponds to the N-typebase/collector 105/106, the interconnect layer 900 corresponds to theP-type base/collector 107/108, the interconnect layer 1000 correspondsto the NPN N-type emitter 104, and the interconnect layer 1100corresponds to the PNP P-type emitter 103, of the thyristor 100 shown inFIG. 1. Each interconnect layer 800, 900, 1000 and 1100, thus, connectsto the corresponding components of each underlying thyristor tile 200 inparallel.

The example layouts of the interconnect layers 800, 900, 1000 and 1100are provided for an overall thyristor device similar to the lateralthyristor device 500 (FIG. 5), i.e., with the thyristor tiles 501-504arranged in a 2×2 array or grid of rows and columns, and the PNP and NPNtiles (501 a-d, 502 a-d, 503 a-d and 504 a-d) arranged in an alternatingconfiguration in a 4×4 array or grid of both rows and columns. Similarlydesigned interconnect layer layouts can be provided for any otherappropriate configuration for any other overall thyristor device, e.g.,including the lateral thyristor devices 600 and 700 of FIGS. 6 and 7,among others.

The proper timing and distribution of electrical signals or currentsprovided to the emitter, base and collector connectors of the PNP andNPN tiles (e.g., 201-204 or 501 a-504 d) is essential for the PNP andNPN tiles to operate in accord with each other, thereby ensuring properfunctioning of the overall thyristor device (e.g., 500, 600 and 700).The complex and novel example layouts or geometry of the interconnectlayers 800, 900, 1000 and 1100, therefore, ensure uniformity in theconnections to the contacts 201 e/f/g, 202 e/f/g, 203 e/f/g and 204e/f/g of the underlying thyristor tiles 200, so that the electricalsignals or currents are properly and evenly distributed thereto, therebyenabling the usage of the unique structure of the thyristor tiles 200and the manufacturability and scalability of the lateral thyristordevices (e.g., 500, 600 and 700). The interconnect layers 800, 900, 1000and 1100 generally connect the contacts or terminals in a manner thatensures that current distribution through the various contacts, vias andinterconnects is approximately equal and avoids current crowdingthroughout the structure of the lateral thyristor devices (e.g., 500,600 and 700).

The example interconnect layer 800 (FIG. 8) generally includes aconductor trace 801 and a plurality of island traces 802, 803 and 804.The conductor trace 801 and the island traces 802-804 may be anyappropriate conductive material, such as copper, aluminum, anothermetal, or a non-metal electrical conductor, depending on the operationalor design requirements or needs of the overall thyristor device or theoverall electronic circuit and/or the availability or cost of materials.The example interconnect layer 800 is formed or deposited on top of thecontacts 201 e/f/g, 202 e/f/g, 203 e/f/g and 204 e/f/g and the fieldoxide layer 303 and with insulation material between each of the traces801-804.

The conductor trace 801 electrically connects to the base/collectorcontacts (e.g., 201 f/g and 202 f/g) and, thus, to the N-type baseregions (e.g., 201 b/c and 202 b/c) of the PNP tiles (e.g., 201 and 202)of the thyristor tiles (e.g., 200) of the overall thyristor device 500.The island traces 802 electrically connect to the base/collectorcontacts (e.g., 203 f/g and 204 f/g) of the NPN tiles (e.g., 203 and204). The island traces 803 electrically connect to the emitter contacts(e.g., 203 e and 204 e) of the NPN tiles (e.g., 203 and 204). The islandtraces 804 electrically connect to the emitter contacts (e.g., 201 e and202 e) of the PNP tiles (e.g., 201 and 202). The contacts 201 e/f/g, 202e/f/g, 203 e/f/g and 204 e/f/g are shown in dashed lines to signify thatthey are disposed under the example interconnect layer 800. Furtherelectrical interconnections from the conductor trace 801 to otherelectronic components of the overall electronic circuit or to externalconnection pads thereof are made from extensions at the periphery (e.g.a peripheral trace 811) of the conductor trace 801 through otherconductor traces, vias and interconnect layers.

The structure of the conductor trace 801 generally includes traces, ortrace portions, such as lateral traces 805, longitudinal traces 806, anddiagonal traces 807. The longitudinal traces 806 provide the electricalcontacts or connections between the conductor trace 801 and thebase/collector contacts (e.g., 201 f/g and 202 f/g) and, thus, to theN-type base regions (e.g., 201 b/c and 202 b/c). The lateral traces 805and the longitudinal traces 806 connect at their endpoints to formgenerally rectangular structures that surround the island traces 804.The lateral traces 805, the longitudinal traces 806, and the diagonaltraces 807 connect at their endpoints to form generally octagonalstructures that surround the island traces 802 and 803. Thus, thediagonal traces 807 connect at their endpoints to vertices of thegenerally rectangular structures formed by the lateral traces 805 andthe longitudinal traces 806. The horizontal thicknesses of the lateraltraces 805, the longitudinal traces 806, the diagonal traces 807, andthe island traces 802-804 are generally selected or designed to allowfor appropriate clear distances between the traces 805-807 of theconductor trace 801 and the island traces 802-804, depending onacceptable interconnect or metallization design rules and theoperational or design requirements or needs of the overall thyristordevice or the overall electronic circuit.

The example interconnect layer 900 (FIG. 9) generally includes aconductor trace 902 and a plurality of island traces 903 and 904. Theconductor trace 902 and the island traces 903 and 904 may be anyappropriate conductive material, such as copper, aluminum, anothermetal, or a non-metal electrical conductor, depending on the operationalor design requirements or needs of the overall thyristor device or theoverall electronic circuit and/or the availability or cost of materials.The example interconnect layer 900 is formed or deposited on top of aninsulator layer (deposited on top of the interconnect layer 800) withelectrical vias (described below) therethrough and with insulationmaterial between each of the traces 902-904.

The conductor trace 902 electrically connects to base/collector vias 905that electrically connect to the island traces 802 (FIG. 8) and to thebase/collector contacts (e.g., 203 f/g and 204 f/g) of the NPN tiles(e.g., 203 and 204) of the thyristor tiles (e.g., 200) of the overallthyristor device 500. The island traces 903 electrically connect toemitter vias 906 that electrically connect to the island traces 803(FIG. 8) and to the emitter contacts (e.g., 203 e and 204 e) of the NPNtiles (e.g., 203 and 204). The island traces 904 electrically connect toemitter vias 907 that electrically connect to the island traces 804(FIG. 8) and to the emitter contacts (e.g., 201 e and 202 e) of the PNPtiles (e.g., 201 and 202). The vias 905, 906 and 907 are shown in dashedlines to signify that they are disposed under the example interconnectlayer 900, e.g., within and through the underlying insulator layer.Further electrical interconnections from the conductor trace 902 toother electronic components of the overall electronic circuit or toexternal connection pads thereof are made from extensions at theperiphery (e.g. a peripheral trace 911) of the conductor trace 902through other conductor traces, vias and interconnect layers.

The structure of the conductor trace 902 generally includes traces, ortrace portions, such as lateral traces 908, longitudinal traces 909, anddiagonal traces 910. The lateral traces 908 provide the electricalcontacts or connections between the conductor trace 902 and thebase/collector vias 905 and, thus, to the island traces 802, thebase/collector contacts (e.g., 203 f/g and 204 f/g), and the P-type baseregions (e.g., 203 b/c and 204 b/c). The lateral traces 908 and thelongitudinal traces 909 connect at their endpoints to form generallyrectangular structures that surround the island traces 903. The lateraltraces 908, the longitudinal traces 909, and the diagonal traces 910connect at their endpoints to form generally octagonal structures thatsurround the island traces 904. Thus, the diagonal traces 910 connect attheir endpoints to vertices of the generally rectangular structuresformed by the lateral traces 908 and the longitudinal traces 909. Theconductor trace 902, therefore, has a generally similar configuration orgeometry as that of the conductor trace 801 (FIG. 8), but therectangular and octagonal structures of the conductor trace 902 areshifted or offset relative to the similar structures of the conductortrace 801, such that the octagonal structures of the conductor trace 902are vertically aligned with the rectangular structures of the conductortrace 801, and the rectangular structures of the conductor trace 902 arevertically aligned with the octagonal structures of the conductor trace801. The horizontal thicknesses of the lateral traces 908, thelongitudinal traces 909, the diagonal traces 910, and the island traces903 and 904 are generally selected or designed to allow for appropriateclear distances between the traces 908-910 of the conductor trace 902and the island traces 903 and 904, depending on acceptable interconnector metallization design rules and the operational or design requirementsor needs of the overall thyristor device or the overall electroniccircuit. For example, in this embodiment, a set of only two vias areshown for each group of the emitter vias 906 and 907 (as opposed to theset of four contacts, as was shown for each group of the contacts 201 e,202 e, 203 e and 204 e in FIG. 8), and the island traces 903 and 904 areshown as small rectangles (smaller than the squares shown for the islandtraces 803 and 804), in order to pass acceptable interconnect ormetallization design rule checks, and so that the overall thyristordevice has optimum performance characteristics.

Although the first example interconnect layer 800 and the second exampleinterconnect layer 900 are shown and described for electricallyconnecting (directly or indirectly) to the PNP base/collector contacts201 f/g and 202 f/g and the NPN base/collector contacts 203 f/g and 204f/g, respectively, it is understood that these electrical connectionsmay be reversed. In other words, in other embodiments, the NPNbase/collector contacts 203 f/g and 204 f/g could be electricallyconnected through the first interconnect layer, and the PNPbase/collector contacts 201 f/g and 202 f/g could be electricallyconnected through the second interconnect layer.

The example interconnect layer 1000 (FIG. 10) generally includes aconductor trace 1003 and a plurality of island traces 1004. Theconductor trace 1003 and the island traces 1004 may be any appropriateconductive material, such as copper, aluminum, another metal, or anon-metal electrical conductor, depending on the operational or designrequirements or needs of the overall thyristor device or the overallelectronic circuit and/or the availability or cost of materials. Theexample interconnect layer 1000 is formed or deposited on top of aninsulator layer (deposited on top of the interconnect layer 900) withelectrical vias (described below) therethrough and with insulationmaterial between each of the traces 1003 and 1004.

The conductor trace 1003 electrically connects to emitter vias 1006 thatelectrically connect to the island traces 903 (FIG. 9) and through tothe emitter vias 906, the island traces 803 (FIG. 8), and the emittercontacts (e.g., 203 e and 204 e) of the NPN tiles (e.g., 203 and 204) ofthe thyristor tiles (e.g., 200) of the overall thyristor device 500. Theisland traces 1004 electrically connect to emitter vias 1007 thatelectrically connect to the island traces 904 and through to the emittervias 907, the island traces 804 (FIG. 8), and the emitter contacts(e.g., 201 e and 202 e) of the PNP tiles (e.g., 201 and 202). The vias1006 and 1007 are shown in dashed lines to signify that they aredisposed under the example interconnect layer 1000, e.g., within andthrough the underlying insulator layer. Further electricalinterconnections from the conductor trace 1003 to other electroniccomponents of the overall electronic circuit or to external connectionpads thereof are made from extensions at the periphery (e.g. lateralperipheral traces 1008 and longitudinal peripheral traces 1009) of theconductor trace 1003 through other conductor traces, vias andinterconnect layers.

The structure of the conductor trace 1003 generally includes traces, ortrace portions, such as first and second sets of diagonal traces 1010and 1011. Each diagonal trace 1010 extends along or parallel to a firstdiagonal direction (e.g., at about a negative 45-degree angle relativeto lateral peripheral traces 1008 and longitudinal peripheral traces1009 or between top left and bottom right). Each diagonal trace 1011extends along or parallel to a second diagonal direction (e.g., at abouta positive 45-degree angle relative to the lateral peripheral traces1008 and the longitudinal peripheral traces 1009 or between top rightand bottom left). In some embodiments, the diagonal traces 1010 and 1011are perpendicular to each other. The diagonal traces 1010 and 1011generally form rhombus shapes, diamond shapes, or 45-degree-rotatedrectangle or square shapes that surround the island traces 1004. Eachdiagonal trace 1010 and 1011 electrically connects (e.g., through theemitter vias 1006, the island traces 903, the emitter vias 906, theisland traces 803, and the emitter contacts 203 e and 204 e) to theN-type emitter regions (e.g., 203 a and 204 a) of the NPN tiles (e.g.,203 and 204) that are aligned along the same diagonal directions. Thehorizontal thicknesses of the diagonal traces 1010 and 1011 and theisland traces 1004 are generally selected or designed to allow forappropriate clear distances between the diagonal traces 1010 and 1011 ofthe conductor trace 1003 and the island traces 1004, depending onacceptable interconnect or metallization design rules and theoperational or design requirements or needs of the overall thyristordevice or the overall electronic circuit.

The example interconnect layer 1100 (FIG. 11) generally includes aconductor trace 1104. The conductor trace 1104 may be any appropriateconductive material, such as copper, aluminum, another metal, or anon-metal electrical conductor, depending on the operational or designrequirements or needs of the overall thyristor device or the overallelectronic circuit and/or the availability or cost of materials. Theexample interconnect layer 1100 is formed or deposited on top of aninsulator layer (deposited on top of the interconnect layer 1000) withelectrical vias (described below) therethrough.

The conductor trace 1104 electrically connects to emitter vias 1107 thatelectrically connect to the island traces 1004 (FIG. 10) and through tothe emitter vias 1007, the island traces 904 (FIG. 9), the emitter vias907, the island traces 804 (FIG. 8), and the emitter contacts (e.g., 201e and 202 e) of the PNP tiles (e.g., 201 and 202) of the thyristor tiles(e.g., 200) of the overall thyristor device 500. The emitter vias 1107are shown in dashed lines to signify that they are disposed under theexample interconnect layer 1100, e.g., within and through the underlyinginsulator layer. Further electrical interconnections from the conductortrace 1104 to other electronic components of the overall electroniccircuit or to external connection pads thereof are made from extensionsat the periphery of the conductor trace 1104 through other conductortraces, vias and interconnect layers.

The structure of the conductor trace 1104 is generally that of a flatplate or sheet with periodically spaced holes or slots 1108. The holes1108 are generally rectangular or square shaped. The holes 1108 preventor mitigate warpage or deformation of the conductor trace 1104 (andpotential damage to adjacent underlying or overlying material layers)when the conductor trace 1104 becomes hot during operation of thethyristor device and the overall electronic circuit. Acceptableinterconnect or metallization design rules typically require such holesto be spaced from via connections. Dotted-line squares 1109 are shown torepresent such a required spacing distance around the emitter vias 1107,so that the emitter vias 1107 are overlaid by a sufficient amount of thematerial of the interconnect layer 1100. The holes 1108, therefore, areshown outside the dotted-line squares 1109. As a result, the holes 1108are horizontally offset from the center of the underlying thyristortiles (e.g., 200). Alternatively, in some embodiments, the conductortrace 1104 of the fourth interconnect layer 1100 could have a generallysimilar configuration or geometry as that of the conductor trace 1003(FIG. 10) of the third interconnect layer 1000, but with the diagonaltraces 1010 and 1011 shifted or offset relative to the similarstructures of the conductor trace 1003, such that the intersections ofthe diagonal traces 1010 and 1011 are vertically aligned with theemitter vias 1107.

Although the third example interconnect layer 1000 and the fourthexample interconnect layer 1100 are shown and described for electricallyconnecting through to the NPN emitter contacts 203 e and 204 e and thePNP emitter contacts 201 e and 202 e, respectively, it is understoodthat these electrical connections may be reversed. In other words, inother embodiments, the PNP emitter contacts 201 e and 202 e could beelectrically connected through the third interconnect layer, and the NPNemitter contacts 203 e and 204 e could be electrically connected throughthe fourth interconnect layer.

Additionally, each of the electrical interconnect or metal layers 800,900, 1000 and 1100 has an outer edge or peripheral trace (e.g., 811,911, 1008/1009) that fully encompasses the entire electricalinterconnect or metal layers 800, 900, 1000 and 1100. In other words,each of the electrical interconnect or metal layers 800, 900, 1000 and1100 is exposed on all four sides. In other words, the electricalinterconnect or metal layers 800, 900, 1000 and 1100 are each configuredto receive an electrical connection thereto at any point along anyperipheral side thereof. Consequently, the electrical interconnections(from the electrical interconnect or metal layers 800, 900, 1000 and1100 to other electronic components of the overall electronic circuit orto external connection pads thereof) can be made on any one or more (orall four) sides of the electrical interconnect or metal layers 800, 900,1000 and 1100. This feature enables the advantage of allowing easyelectrical connection to the thyristor device 100 and placement of thethyristor device 100 at almost any available location within the overallelectronic circuit or integrated circuit. In contrast, many prior artthyristor designs require electrical connections to be on a particularside of the thyristor; thereby restricting the potential for placing thethyristor within an overall integrated circuit.

FIGS. 12-18 and 20-26 show simplified graphs indicating the performanceof example improved horizontal or lateral thyristor devices formed witha plurality of horizontal or lateral thyristor tiles (e.g., similar tothe thyristor tile 200 shown in FIGS. 2-4), in accordance with someembodiments. The data available in these graphs illustrate that theexample improved horizontal or lateral thyristor devices perform orfunction as well as, or better than, a conventional thyristor device.

FIGS. 12 and 13 show simplified graphs 1200 and 1300 of reverse diodebreakdown current (ID) versus voltage (VD) curves (I-V curves), andFIGS. 14 and 15 show simplified graphs 1400 and 1500 of SCR breakdownI-V curves, for an example thyristor device. The example thyristordevice in these tests incorporates a 4×4 array or grid of thyristortiles (e.g., each similar to the thyristor tile 200). In the reversediode configuration for the graphs 1200 and 1300, a bias voltage isapplied to the N-type base/collector (e.g., 105 and 106 of FIG. 1, and201 b/c and 202 b/c of FIG. 2), a ground is applied to the P-typebase/collector (e.g., 107 and 108 of FIG. 1, and 203 b/c and 204 b/c ofFIG. 2), and the PNP and NPN emitters (e.g., 103 and 104 of FIG. 1, and201 a, 202 a, 203 a and 204 a of FIG. 2) are floating. In the SCRconfiguration for the graphs 1400 and 1500, a bias voltage is applied tothe PNP emitter (e.g., 103 of FIG. 1, and 201 a and 202 a of FIG. 2) andthe N-type base/collector (e.g., 105 and 106 of FIG. 1, and 201 b/c and202 b/c of FIG. 2), and a ground is applied to the NPN emitter (e.g.,104 of FIG. 1, and 203 a and 204 a of FIG. 2) and the P-typebase/collector (e.g., 107 and 108 of FIG. 1, and 203 b/c and 204 b/c ofFIG. 2).

The I-V curves 1300 and 1500 are provided with a linear scale for boththe current and voltage, which, therefore, also allows for presentationof negative current and voltage values. The I-V curves 1200 and 1400 areprovided with a logarithmic scale for the current (ID) and a linearscale for the voltage (VD), thereby showing enhanced details in the lowvoltage range. These tests were performed with direct current (DC) I-Vsweeps from less than −1.0 volts to greater than 22 volts. All of thegraphs show that the example thyristor device provided excellent voltageblocking capabilities up to about 22 volts. Additionally, the I-V curves1200 and 1400 indicate that the thyristor device exhibited slightly moreleakage current in the SCR configuration than in the reverse diodeconfiguration.

FIGS. 16-18 show simplified current-voltage (I-V) and leakage currentgraphs 1601, 1602, 1701, 1702, 1801 and 1802 for the results oftransmission line pulse (TLP) tests for three example horizontal orlateral thyristor devices (e.g., tiled SCR devices) formed with aplurality of horizontal or lateral thyristor tile (e.g., each similar tothe thyristor tile 200 shown in FIGS. 2-4), in accordance with someembodiments. The first example thyristor, or tiled SCR, device used forthe tests for graphs 1601 and 1602 included a 4×4 array or grid of thethyristor tiles (e.g., each similar to the thyristor tile 200) and hadhorizontal length/width dimensions, or footprint, of about 33 μm by 33μm. The second example thyristor, or tiled SCR, device used for thetests for graphs 1701 and 1702 included a 5×5 array or grid of thethyristor tiles (e.g., each similar to the thyristor tile 200) and hadhorizontal length/width dimensions of about 41 μm by 41 μm. The thirdexample thyristor, or tiled SCR, device used for the tests for graphs1801 and 1802 included a 6×6 array or grid of the thyristor tiles (e.g.,each similar to the thyristor tile 200) and had horizontal length/widthdimensions of about 49 μm by 49 μm.

To generate each of the graphs 1601, 1602, 1701, 1702, 1801 and 1802, atrigger voltage of about one volt was used, as indicated by a verticaldashed line 1803. The graphs 1602, 1702 and 1802 show thecurrent-voltage characteristics (bottom horizontal axis) of the threeexample thyristors. The graphs 1601, 1701 and 1801 show the leakagecurrent (top horizontal axis on a logarithmic scale) for the threeexample thyristors. The leakage current for each example thyristor isshown as approximately 1E-11 Amps, as indicated by the vertical portionof the graphs 1601, 1701 and 1801. The point at which the graphs 1601,1701 and 1801 turn almost horizontal represents the point at which theexample thyristor becomes damaged, i.e., the leakage current increasessignificantly. For the third (6×6) example thyristor, for example, thecurrent at which the thyristor became damaged was about 7.8 Amps(indicated by horizontal dashed line 1804), which is a relatively largecurrent for this type of device. The maximum current density (Jmax) atthis point can then be calculated based on the above mentioneddimensions of the third example thyristor. Similar calculations can bemade for the first and second example thyristors.

With the data shown by the graphs 1601, 1602, 1701, 1702, 1801 and 1802and the above mentioned dimensions, it is shown or calculated that theexample thyristor devices exhibited maximum current density (Jmax)capabilities of more than 3 mA/μm², which is very robust for SOItechnology. For example, the Jmax for the first example thyristor deviceis about 3.021 mA/μm², the Jmax for the second example thyristor deviceis about 3.107 mA/μm², and the Jmax for the third example thyristordevice is about 3.310 mA/μm². The maximum current density results forthe larger example thyristor devices are slightly higher than those forthe smaller example thyristor devices, which is the opposite of theproportionality relationship for conventional thyristor devices (whereinlarger conventional thyristor devices typically exhibit smaller maximumcurrent densities due to current crowding effects, particularly in SCRconfigurations). In other words, the robustness of the structure wasslightly greater for the larger structures. Additionally, the examplethyristors exhibited relatively uniform current capabilities, which ishighly significant for ESD protection for an SOI-based device. Thedirect proportionality relationship between the size of the examplethyristor devices and the maximum current density is, thus, anunexpected result. Additionally, with this data and information, it isfurther shown or calculated that the example thyristor devices exhibitedrelatively low on resistance (Ron) for the given footprint dimensions,or device sizes. For example, the Ron for the first example thyristordevice is about 1.445Ω, the Ron for the second example thyristor deviceis about 0.975Ω, and the Ron for the third example thyristor device isabout 0.616Ω. It is thus shown that thyristor devices formed with aplurality of the thyristor tiles 200 have excellent, and in some casesbetter than expected, performance characteristics.

FIG. 19 shows the simplified schematic diagram of the thyristor 100 ofFIG. 1, but with optional trigger elements (e.g., NMOS trigger elements1901-1905), with connections shown in dashed lines for variousembodiments. Although all of the optional trigger elements 1901-1905 areshown in the same drawing, it is understood, however, that not all wouldbe used at the same time. For example, the optional trigger element 1901is a “top” trigger connected between the P-type emitter 103 and theP-type base/collector 107/108. The optional trigger element 1902 is a“middle” trigger connected between the P-type base/collector 107/108 andthe N-type base/collector 105/106. The optional trigger element 1903 isa “bottom” trigger connected between the N-type base/collector 105/106and the N-type emitter 104. The optional trigger element 1904 is an NMOSbased electrostatic discharge (ESD) protection diode for use in someembodiments with the top trigger element 1901 and is connected betweenthe N-type emitter 104 and the P-type base/collector 107/108. Theoptional trigger element 1905 is an NMOS based ESD diode for use in someembodiments with the bottom trigger element 1903 and is connectedbetween the P-type emitter 103 and the N-type base/collector 105/106.The NMOS based ESD diode trigger elements 1904 and 1905 enablebidirectionality for the thyristor. Additionally, instead of the NMOStrigger elements shown, alternative embodiments may use any appropriatetrigger elements, such as a chain of forward biased diodes (e.g., witheach diode providing about 0.7 volts, which can be stacked depending ondesign requirements) or one or more Zener diodes. Some of these types oftrigger elements are difficult to implement in a bulk semiconductordesign, but the design of the thyristor 100 enables tremendousflexibility in the use of any of these types of trigger elements in abulk implementation or SOI implementation. Furthermore, although notshown, some of the trigger elements may be provided with resistors(e.g., between the bases and emitters of the thyristor 100) to enableturning off the thyristor 100 and fine tuning of the trigger parameters.

FIGS. 20-25 show simplified current-voltage (I-V) graphs 2000, 2100,2200, 2300, 2400 and 2500 indicating the performance of an examplehorizontal or lateral thyristor device formed with a plurality of thethyristor tiles (e.g., each similar to the thyristor tile 200) in an SCRconfiguration and with or without different ones or combinations of thetrigger elements 1901-1905 (FIG. 19), in accordance with someembodiments. Each graph 2000-2500, thus, corresponds to a differenttrigger configuration. FIG. 26 shows all of the I-V graphs 2000-2500together for comparison. The I-V graphs 2000-2500 are provided with alogarithmic scale for the current (ID) and a linear scale for thevoltage (VD) and were generated with a DC I-V sweep from about 0-1 voltsto about 12-15 volts.

The I-V graph 2000 was generated with an example thyristor device notusing any of the trigger elements 1901-1905. The I-V graph 2100 wasgenerated with an example thyristor device using only the top triggerelement 1901. The I-V graph 2200 was generated with an example thyristordevice using the top trigger element 1901 in combination with the NMOSbased ESD diode trigger element 1904. The I-V graph 2300 was generatedwith an example thyristor device using only the middle trigger element1902. The I-V graph 2400 was generated with an example thyristor deviceusing only the bottom trigger element 1903. The I-V graph 2500 wasgenerated with an example thyristor device using the bottom triggerelement 1903 in combination with the NMOS based ESD diode triggerelement 1905. The I-V graphs 2000-2500 demonstrate that the thyristorperforms very similarly with each trigger configuration up to about 12volts. The I-V graphs 2000-2500 in FIGS. 20-26, thus, demonstrate thatthe thyristor devices formed with a plurality of the thyristor tiles 200can be implemented with the trigger elements 1901-1905, as needed tocontrol the trigger voltage, with excellent results.

FIG. 27 shows a simplified flowchart for a process 2700 for forming thethyristor devices with the thyristor tiles 200, in accordance with oneor more example embodiments. The particular steps, combination of steps,and order of the steps are provided for illustrative purposes only.Other processes with different steps, combinations of steps, or ordersof steps can also be used to achieve the same or similar result.Features or functions described for one of the steps may be performed ina different step in some embodiments. Furthermore, additional steps notexplicitly shown or described may be performed before or after or as asub-portion of the steps shown. Additionally, the above description ofthe thyristor device (e.g., with the thyristor tiles 200 and theelectrical interconnect or metal layers 800, 900, 1000 and 1100) and thefollowing process 2700 for the formation thereof illustrate that, insome embodiments, the thyristor device can be formed as part of orwithin an overall CMOS process flow without the use of additional masksor changes to the conventional process flow. Thus, the thyristor devicecan be formed along with or simultaneously with MOSFET devices (orportions thereof) of the overall electronic circuit or integratedcircuit. The ability to be formed as part of a conventional CMOS processflow provides a significant advantage (over many prior art thyristordesigns and formation processes) for incorporating the thyristor deviceinto the overall electronic circuit or integrated circuit. For example,the lack of additional masks or process changes means that the inclusionof the thyristor device in the overall electronic circuit does notrequire any additional costs or fabrication time.

Upon starting, a semiconductor wafer is provided (at 2701). In someembodiments, the semiconductor wafer is already a fully formed SOI waferat this point. In some embodiments, the semiconductor wafer is a bulksemiconductor wafer, i.e., without a buried oxide of an SOI wafer. Insome embodiments, providing the semiconductor wafer at 2701 includesforming a buried oxide layer (e.g., for the BOX layer 301 in FIGS. 3 and4) on a substrate (e.g., the underlying substrate 302 in FIGS. 3 and 4)and forming a semiconductor layer (e.g., an intrinsic layer, N-minuslayer, or P-minus layer into and onto which the above described activelayer is to be formed) on the buried oxide layer (e.g., by epitaxialgrowth or layer transfer techniques), thereby forming an SOI wafer.

Some of the subsequent structure formation steps are performed, forexample, by patterning a photoresist over the semiconductor layer andimplanting dopants of the appropriate N and P conductivity to form theactive region of the thyristor tile 200. Additionally, these formationsteps can be performed in conjunction with forming other structures orcomponents (e.g., of MOSFETs) of the overall electronic circuit orintegrated circuit of which the resulting horizontal or lateralthyristor device is a part.

At 2702, to begin forming the active region, an N-well is formed as abase region (e.g., the N-well base regions 201 d and 202 d in FIGS. 2-4)in the semiconductor layer for the PNP tiles 201 and 202. At 2703, aP-well is formed as a base region (e.g., the P-well base regions 203 dand 204 d in FIGS. 2-4) in the semiconductor layer for the NPN tiles 203and 204. Alternatively, (at 2701-2703) one of the two wells (N-well orP-well) is provided or formed as an initial N-minus or P-minus epitaxiallayer (e.g., as the semiconductor layer on top of the BOX layer 301)that also forms a semiconductor layer into and onto which the MOSFETs ofthe overall electronic circuit are also formed. The other of the twowells is then formed by appropriate implantation of the opposite P or Ntype dopant.

At 2704, regions of the field oxide 303 are formed on the active regionof the thyristor tile 200. Additionally, areas of the field oxide 303are removed from portions of locations where the emitter regions 201 a,202 a, 203 a and 204 a and the base/collector regions 201 b/c, 202 b/c,203 b/c and 204 b/c (or the connector regions associated therewith) willbe, so that subsequent processing steps can implant or deposit dopantsor materials through these openings in the field oxide 303.

At 2705, N-type regions (e.g., for the N-type base/collector regions 201b/c and 202 b/c and the N-type emitter regions 203 a and 204 a in FIGS.2-4) are formed by N dopant implantation within the N-well and P-wellbase regions 201 d, 202 d, 203 d and 204 d, e.g., at the appropriateremoved portions of the field oxide 303. At 2706, N+ regions (e.g., forthe N+ base/collector connector regions, such as 202 j/k, and the N+emitter connector region, such as 204 i) are formed by additional Ndopant implantation within the N-type base/collector regions 201 b/c and202 b/c and the N-type emitter regions 203 a and 204 a.

At 2707, P-type regions (e.g., for the P-type base/collector regions 203b/c and 204 b/c and the P-type emitter regions 201 a and 202 a in FIGS.2-4) are formed by P dopant implantation within the N-well and P-wellbase regions 201 d, 202 d, 203 d and 204 d, e.g., at the appropriateremoved portions of the field oxide 303. At 2708, P+ regions (e.g., forthe P+ base/collector connector regions, such as 204 j/k, and the P+emitter connector region, such as 201 i and 202 i) are formed byadditional P dopant implantation within the P-type base/collectorregions 203 b/c and 204 b/c and the P-type emitter regions 201 a and 202a.

At 2709, electrically conductive material (e.g., metals, etc.) can bedeposited to form the emitter and base/collector contacts 201 e/f/g, 202e/f/g, 203 e/f/g and 204 e/f/g on the connector regions (such as 201 i,202 i/j/k, 204 i/j/k, and others not shown or labeled in the drawings).At 2710, the series of alternating insulator layers (with electricallyconductive vias therethrough, e.g., as shown in FIGS. 9-11) andelectrically conductive interconnect layers (e.g., the electricalinterconnect or metal layers 800, 900, 1000 and 1100, as shown in FIGS.8-11) are formed, thereby electrically connecting the thyristor tiles200 through the contacts 201 e/f/g, 202 e/f/g, 203 e/f/g and 204 e/f/gto the other structures or components of the overall electronic circuitor integrated circuit of which the resulting horizontal or lateralthyristor device is a part. The overall electronic circuit or integratedcircuit is further processed into an integrated circuit package.

Reference has been made in detail to embodiments of the disclosedinvention, one or more examples of which have been illustrated in theaccompanying figures. Each example has been provided by way ofexplanation of the present technology, not as a limitation of thepresent technology. In fact, while the specification has been describedin detail with respect to specific embodiments of the invention, it willbe appreciated that those skilled in the art, upon attaining anunderstanding of the foregoing, may readily conceive of alterations to,variations of, and equivalents to these embodiments. For instance,features illustrated or described as part of one embodiment may be usedwith another embodiment to yield a still further embodiment. Thus, it isintended that the present subject matter covers all such modificationsand variations within the scope of the appended claims and theirequivalents. These and other modifications and variations to the presentinvention may be practiced by those of ordinary skill in the art,without departing from the scope of the present invention, which is moreparticularly set forth in the appended claims. Furthermore, those ofordinary skill in the art will appreciate that the foregoing descriptionis by way of example only, and is not intended to limit the invention.

What is claimed is:
 1. A thyristor tile comprising: first and second PNPtiles; and first and second NPN tiles; wherein: each PNP tile isadjacent to both NPN tiles; and each NPN tile is adjacent to both PNPtiles.
 2. The thyristor tile of claim 1, wherein: the first and secondPNP tiles have a first orientation; and the first and second NPN tileshave a second orientation that is perpendicular to the firstorientation.
 3. The thyristor tile of claim 2, wherein: each of thefirst and second PNP tiles have an N-type base region and a P-typeemitter region aligned in the first orientation; and each of the firstand second NPN tiles have a P-type base region and an N-type emitterregion aligned in the second orientation.
 4. The thyristor tile of claim3, wherein: each N-type base region is aligned in the first orientationwith the N-type emitter region of one of the first and second NPN tilesand is an N-type collector region of that NPN tile; and each P-type baseregion is aligned in the second orientation with the P-type emitterregion of one of the first and second PNP tiles and is a P-typecollector region of that PNP tile.
 5. The thyristor tile of claim 3,wherein: the first and second PNP tiles each have a second N-type baseregion aligned in the first orientation with the first N-type baseregion and the P-type emitter region; and the first and second NPN tileseach have a second P-type base region aligned in the second orientationwith the first P-type base region and the N-type emitter region.
 6. Thethyristor tile of claim 5, further comprising: a first interconnectlayer that electrically connects the N-type base regions of the firstand second PNP tiles; a second interconnect layer that electricallyconnects the P-type base regions of the first and second NPN tiles; athird interconnect layer that electrically connects the N-type emitterregions of the first and second NPN tiles; and a fourth interconnectlayer that electrically connects the P-type emitter regions of the firstand second PNP tiles.
 7. The thyristor tile of claim 6, wherein: thethyristor tile is formed with a horizontal longitudinal dimension and ahorizontal lateral dimension; the first interconnect layer includes 1)first island traces that electrically connect to the P-type emitterregions, 2) second island traces that electrically connect to the N-typeemitter regions, 3) third island traces that electrically connect to theP-type base regions, and 4) first lateral, longitudinal and diagonaltraces that electrically connect to the N-type base regions and thatsurround the first, second and third island traces; the secondinterconnect layer includes 1) fourth island traces that electricallyconnect to the P-type emitter regions, 2) fifth island traces thatelectrically connect to the N-type emitter regions, and 3) secondlateral, longitudinal and diagonal traces that electrically connect tothe P-type base regions and that surround the fourth and fifth islandtraces; and the third interconnect layer includes 1) sixth island tracesthat electrically connect to the P-type emitter regions, and 2) firstand second sets of diagonal traces that electrically connect to theN-type emitter regions that are aligned along the same diagonals andthat surround the sixth island traces.
 8. The thyristor tile of claim 7,wherein: the first lateral, longitudinal and diagonal traces form firstrectangular structures that surround the first island traces and formfirst octagonal structures that surround the second and third islandtraces; the second lateral, longitudinal and diagonal traces form secondrectangular structures that surround the fifth island traces and formsecond octagonal structures that surround the fourth island traces; andthe first and second sets of diagonal traces form rhombus structuresthat surround the sixth island traces.
 9. The thyristor tile of claim 1,wherein: each NPN tile is formed within a P-well base; each PNP tile isformed within an N-well base; and the P-well bases are adjacent to theN-well bases, except at a corner between all four N-wells and P-wells.10. The thyristor tile of claim 1, wherein: the first PNP tile is in afirst quadrant of the thyristor tile; the first NPN tile is in a secondquadrant of the thyristor tile, the second quadrant being locatedadjacent to the first quadrant; the second PNP tile is in a thirdquadrant of the thyristor tile, the third quadrant being locatedadjacent to the second quadrant, and the third quadrant being diagonallylocated from the first quadrant; and the second NPN tile is in a fourthquadrant of the thyristor tile, the fourth quadrant being locatedadjacent to the first and third quadrants, and the fourth quadrant beingdiagonally located from the second quadrant.
 11. A thyristor comprisinga plurality of the thyristor tile of claim 10, wherein: the first NPNtile in the second quadrant of a first one of the plurality of thethyristor tile is located adjacent to the first PNP tile in the firstquadrant of a second one of the plurality of the thyristor tile; and afirst N-type base region of the first PNP tile in the first quadrant ofthe second one of the plurality of the thyristor tile is a first N-typecollector region of the first NPN tile in the second quadrant of thefirst one of the plurality of the thyristor tile.
 12. The thyristor ofclaim 11, wherein: the first NPN tile in the second quadrant of thefirst one of the plurality of the thyristor tile is located adjacent tothe second PNP tile in the third quadrant of a third one of theplurality of the thyristor tile; and a first P-type base region of thefirst NPN tile in the second quadrant of the first one of the pluralityof the thyristor tile is a first P-type collector region of the secondPNP tile in the third quadrant of the third one of the plurality of thethyristor tile.
 13. A thyristor comprising: a plurality of PNP tiles;and a plurality of NPN tiles; wherein the PNP tiles and NPN tiles arearranged in an alternating configuration in both rows and columns. 14.The thyristor of claim 13, wherein: each PNP tile is adjacent to atleast two of the NPN tiles; and each NPN tile is adjacent to at leasttwo of the PNP tiles.
 15. The thyristor of claim 13, wherein: each PNPtile has at least one base region that is also a collector region of anadjacent NPN tile; and each NPN tile has at least one base region thatis also a collector region of an adjacent PNP tile.
 16. The thyristor ofclaim 13, wherein: the PNP tiles have a first orientation; and the NPNtiles have a second orientation that is perpendicular to the firstorientation.
 17. The thyristor of claim 16, wherein: each PNP tile hasfirst and second N-type base regions and a P-type emitter region, theP-type emitter region being located between the first and second N-typebase regions, and the first and second N-type base regions and theP-type emitter region being aligned in the first orientation; and eachNPN tile has first and second P-type base regions and an N-type emitterregion, the N-type emitter region being located between the first andsecond P-type base regions, and the first and second P-type base regionsand the N-type emitter region being aligned in the second orientation.18. The thyristor of claim 17, wherein: at least one of the first andsecond N-type base regions of each PNP tile is aligned in the firstorientation with the N-type emitter region of an adjacent one of the NPNtiles; the at least one of the first and second N-type base regions ofeach PNP tile is also an N-type collector region of the adjacent one ofthe NPN tiles; at least one of the first and second P-type base regionsof each NPN tile is aligned in the second orientation with the P-typeemitter region of an adjacent one of the PNP tiles; and the at least oneof the first and second P-type base regions of each NPN tile is also aP-type collector region of the adjacent one of the PNP tiles.
 19. Thethyristor of claim 18, further comprising: a first interconnect layerthat electrically connects the N-type base regions of the PNP tiles andthe N-type collector regions of the NPN tiles, the first interconnectlayer including first traces that surround the P-type emitter regions,the N-type emitter regions, and the P-type base regions in a first planevertically offset therefrom; a second interconnect layer thatelectrically connects the P-type base regions of the NPN tiles and theP-type collector regions of the PNP tiles, the second interconnect layerincluding second traces that surround the P-type emitter regions and theN-type emitter regions in a second plane vertically offset therefrom; athird interconnect layer that electrically connects the N-type emitterregions of the NPN tiles, the third interconnect layer including thirdtraces that surround the P-type emitter regions in a third planevertically offset therefrom; and a fourth interconnect layer thatelectrically connects the P-type emitter regions of the PNP tiles. 20.The thyristor of claim 19, wherein: the first traces form firstrectangular structures that surround the P-type emitter regions and formfirst octagonal structures that surround the N-type emitter regions andthe P-type base regions; the second traces form second rectangularstructures that surround the N-type emitter regions and form secondoctagonal structures that surround the P-type emitter regions; and thethird traces include diagonal traces that form rhombus structures thatsurround the P-type emitter regions.
 21. The thyristor of claim 19,wherein: the first, second, third and fourth interconnect layers areconfigured to receive an electrical connection thereto at any pointalong any peripheral side thereof for electrical interconnections toother electronic components of an overall electronic circuit of whichthe thyristor is a part.
 22. The thyristor of claim 13, wherein: the PNPtiles and the NPN tiles are formed within a CMOS process flowsimultaneously with portions of MOSFET devices of an overall electroniccircuit of which the thyristor is a part.